Means for indicating aircraft flight condition



1945- v. DE sAMoNoW 3 M MEANS FOR INDICATTNG AIRCRAFT FLIGHT CONDITION Filed Sept. 5, 1942 INVENTOi? 3 I 7 ll 5 ASS L me iq/ma/vow/ yam!" a m MW ATTORNEY rea hed no or, loco outrun Wfi WK ENDEKJAHWG mom oorlomon This invention relates to rncnno for indicating the flight condition oi oir pianos. eomciuliy to warn the pilot by either on cudlblo or viouul oional of a stall condition and to give an lndicntion or correct glide conditions.

Th angle and speed oi attack of the wlndo of a plane relative to the air determined the lift component of the force developed. Einoe it is the lift comDonent which counterocto gravity the plane will fall when that component becomes less than gravity. The lift force is produced by the combination of o negative presoure on top of the wing and a positive pressure on the bottom. and it is necessary in order to avoid a stal condition. that is, e condition where the lift component is insufficient to support the plane. to keep the areas of negative and positive preeoures properly disposed and separate. The speed and ultitude of the wings are therefore both rector-o oi the flight condition, and it requlres'leoc speed to keep the centers of pressure on the winds oorrectly disposed when flying straight cheod at the proper angle oi otooclr, then when climbing or banking. The pressures at pointe on the airfoil surfaces are a function 0! the speed and uncle of attack Therefore it this pressure be known it will be an indication of the flight condition.

According to this inventlomthereiore, menus are provided to compute the dynamic preiulureo at selected points on the airfoil suriucee with o predetermined minimum pressure, and. to indicate the result of the comparison.

I am aware that differential devices oi this denerol character hove been employed to compare to static pressure with o dynamic 'preosure obtained by a device in the nature-oi o Pilot tube, und utilize the difi'erencc inpreeoure to indicate the speed of a craft. While my invention utilioeo that general principle, its purpose is to embody it in suficiently flexible iorm to adopt it for one in connection with air pinned each or which has its own indivldual charocteristlcs which vary with different load conditions.

Moreover it is elemental that flight conditions vary with changes in altitude, more speed heinn required to develop ouiflcient lilting-force no the air becomes less dense. This is automatically taken care of in accordance with this invention because the minimum value of the comporinn or reference pressure remainn constant irrespective oi the elevation. and, since the compared preosure is a iunction oi the speed, it will he necessary to incrcaeo the speed with the elevation to keep the indication in the safety runoe.

The diflcrentiul or emporium: device in cult nhly n cooling divided into two chumbers by u di on one side of which is the predetei mined minimum pressure and on the other aide the vnrlnble pressure. Preferably the chamber the pressure in which is compared will be con nected with two widely separated orifices, for exsimple, one on each wing, so that the measure will be the overuse of the two points. The referonce pressure. thot is, that on the opposite side of the diaphragm. must be at or above the predetermined minimum vulue as determined by the spring loading, and should exceed the minimum or atoll condition pressure on the first side.

It is euituhic therefore to employ a reducing or regulating vulve in the line providing the rcferencc preomire which may be variably set to give be connected to open the bleeding valve so no to reduce the compared pressure and thus cause the danger signal to be displayed at at greater cirioil nurioco pressure during very steep turns than when in normal flight. r Y

The invention includes other features which will oppeor irom the following description or the illuatruted embodiment of the invention.

Fig. i is u dionrnmmetic representation oi an embodiment of the invention an npplied to on air plane, parts being broken owoy.

Fig. 2 in n detail in plnn oi the instruments showing the relation of the indicators to the win clowo.

m. 3 is c. detail in plan of one oi the indicatort.

The ports l end ll may well be considered pordone of the two Wings of on air plane with the instruments 8 incl ii located in the fuselage within view oi the pilot. Openings 5. 3, l and 8 are pressure orifices on on nix-loll surface, such no the leading edge oi the wings. These openings are connected by tubes to the diiicrential devices as will he deocrihod. These devices as shown ore cubotontiuiiy identical. Reference will first be mode to device ll.

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ace in velcciiy a? @116 's" For: reasons awve menzmnecl the writ 05 the K135153211, s-,ujustamu differential pressums sh ank? be Mwiflarl an sicep valw acljanent the EL'JIGMDLG. the banks '09 prevent gaming mm a Z1. m s znmvmimg' a1 vm'iabla 0p be when (:Ezre 01" by connecting tum m ziicatm canmcimm to film M33231: device m eaxhmast r932 tnmugh M m w w w w m mm 11 my buwd mm, L mm L; M n2 w 1 1 aseoeee tion comprising means forming two substantially spaced pressure openings on airfoil surfaces positioned to develop a dynamic pressure which falls below a predetermined minimum value Just prior to stall conditions, a casing disposed substantially midway between the openings, a flexible diaphragm mounted in the casing, two tubes of substantially equal length leading from the respective openings and communicating with a common inlet into the casing on one side of the diaphragm, adjustable valve means adjacent the junction of the two tubes providing a variable leakage opening to control the dynamic pressure, means forming a third pressure opening on an airfoil surface, a third tube leading from the third opening to the casing on the opposite side of the diaphragm, a regulating pressure valve in the third tube to maintain pressure on said last side of said diaphragm which is at or above said predetermined minimum pressure, and an indicator connected to the diaphragm to be operated thereby.

5. Means for indicating aircraft flight con tion comprising a casing having a movable member positionable by the relative pressures upon its opposite sides, means for developing a pressure upon one side of the member which is at or above a predetermined minimum pressure, a pressure tube leading into the casing on the opposite side of the member and having its open pressure end exposed at an airfoil surface to develop on the opposite side of the member a dynamic pressure which is a function of the speed of the aircraft and becomes less than said minimum just prior to stall conditions, adjustable valve means in the tube providing a variable leakage opening for the air to regulate the dynamic pressure, means responsive to the rate of turning of the aircraft operative to modify the pressure on one side of the diaphragm, and an indicator operated by the movement of the member.

6. Means for indicating aircraft flight condition. comprising means forming two substantially spaced pressure openings on airfoil surfs ces positioned to develop a dynamic pressure which falls below a predetermined minimum value just prior to stall conditions, a casing disposed substantially midway between the openings, a lienible diaphragm mounted in the casing, two tubes of substantially equal length leading from the respective openings and communicating with a common inlet into the casing on one side of the diaphragm, adjustable valve means adjacent the junction of the two tubes providing a variable leakage opening, means forming a third pres sure opening on an airfoil surface, a third tube leading from the third opening to the casing on the opposite side of the diaphragm, a regulating pressure valve in the third tube to maintain a pressure on said last side of said diaphragm which is at or above said predetermined minimum pressure, means responsive to the rate of turning of the aircraft operative to modify the pressure on one side of the diaphragm, and an indicator connected to the diaphragm to be op erated thereby.

VASSILY an SAMSONOW. 

